1. Field of the Invention
The invention relates to a magnetic head comprising a head core part which includes at least either a magnetic head element for writing or a magnetic head element for reading formed on a base body, a method of manufacturing the same, and a magnetic disk apparatus.
2. Description of the Related Art
In recent years, research and development for improving surface recording density has been actively carried out in the field of magnetic recording devices such as computers. FIG. 11 shows a general configuration of a magnetic disk apparatus as an example of a magnetic recording device. In the magnetic disk apparatus, a magnetic head slider (also simply referred as magnetic head or head in the followings) 100 including a base body and a head core part formed on the base body is placed so as to face a surface of a magnetic disk (also simply referred as disk in the followings) 110 as a recording medium. Although, a magnetic disk apparatus usually has a plurality of magnetic disks and one magnetic head slider is respectively provided on each surface of the magnetic disks, only one magnetic head slider and one magnetic disk are shown in FIG. 11 and the rest of them are omitted therein. The magnetic disk 110 rotates by a spindle motor 111. The magnetic head 100 is held by the end portion 132q of a suspension 132. The other end portion 132q of the suspension 132 is attached to the end portion of a drive arm 131. The magnetic disk apparatus also comprises a carriage unit 120 at the base side of the drive arm 131 for positioning the magnetic head 100 on the track of the magnetic disk 110. The carriage portion 120 has a carriage 122 which swings about the shaft 121, and an actuator 123 composed of a voice coil motor and so on. The actuator 123 drives the carriage 122 to swing about the shaft 121 so that the magnetic head 100 can be moved in the radial direction (arrow direction shown in FIG. 11) of the magnetic disk 110.
In the magnetic disk apparatus with such a configuration, in general, recording/reproducing of information is performed as follows. The head 100 pressed by the suspension 132 is in contact with the disk 110 when the disk 110 is not rotating. When the disk 110 is rotated, an airflow generates between the head 100 and the disk 110 so that a lift is created. As a result, the head 100 flys to leave from the surface of the disk 110, and performs recording/reproducing of information by relatively shifting on the disk 110 while holding a small space in therebetween by keeping the balance of the lift and the pressure from the suspension 132. Such a recording/reproducing system is called CSS (Contact-Start-Stop) system.
The surface where the magnetic head and the magnetic disk are contacted together is preferable to be smooth in order for the magnetic disk apparatus to have high surface recording density. Particularly, in the device with CSS system, it is preferable that the state both contacted surfaces of the head and the disk does not change (that is, excellent in CSS characteristic) even after repeating the CSS operation for a number of times. However, when both of the surface of the head and the disk are smooth, the head and the disk adsorb each other resulting in deterioration of the CSS characteristic. Accordingly, in the magnetic disk apparatus of the related art, the adsorb phenomenon is avoided by roughing either one of the surface of the head or the disk.
An example of roughing the surface of the disk is disclosed in Japanese Patent Application Laid-open Sho 61-246380, Hei 5-94618 and Hei 5-159276. In Japanese Patent Application Laid-open Sho 61-246380, a method of roughing the surface of the disk as a recording medium by applying a heat treatment in an oxygen atmosphere to a magnetic disk substrate with nickel (Ni) alloy plating layer formed on its surface is disclosed. In Japanese Patent Application Laid-open Hei 5-94618, a method of adjusting the roughness of the disk surface by applying a heat treatment to a magnetic disk substrate made of amorphous carbon under the existence of oxidation gas is disclosed. In Japanese Patent Application Laid-open Hei 5-159276, a magnetic disk is disclosed in which the surface is roughed by, for example, anodizing titanium (Ti) or titanium alloy to form titanium oxide (TiO2).
However, in a case where the surface of the magnetic disk is made rough as described, the head core part may be damaged when the disk and the head are in contact.
On the other hand, for example, Japanese Patent Application Laid-open Sho 63-37874 and Hei 6-44717 disclose an example of roughing the surface, facing the magnetic disk, of the magnetic head (referred as ABS (Air Bearing Surface) or air bearing surface in the followings). Japanese Patent Application Laid-open Sho 63-37874 discloses, under consideration of the contact area of the ABS and the surface of the magnetic disk, a magnetic head constructed so as to control the contact area smaller than a predetermined value. However, the specific control method is not disclosed. Japanese Patent Application Laid-open Hei 6-44717 discloses, under consideration of the roughness of the ABS, a magnetic head in which the roughness of the surface is limited. However, the specific method for implementing the control of the roughness of the surface is not disclosed therein.
Further, Japanese Patent Application Laid-open Hei 2-95807 discloses a method of obtaining a plurality of magnetic heads by forming a plurality of head cores on a base body made of sintered ferrite and then cutting the base body. With this method, coming-off of the grains from the surface areas of the base body can be prevented by applying a heat treatment to the base body in an oxygen atmosphere. However, articles regarding roughing the ABS is not disclosed.
As represented by the two examples described above, logic of the magnetic head with the roughed ABS has been brought up, however, specific and effective means for implementing it has not been contrived. For example, the ABS can be made rough by polishing the surface using a rough abrasive grain. However, there is a problem with this method that the head core part is damaged while polishing. Accordingly, it is desired to develop a magnetic head with the ABS being roughed without damaging the head core part.
Furthermore, a method of manufacturing alumina-type materials for magnetic head is disclosed in Japanese Patent Application Laid-open Sho 61-50906, however, a method of manufacturing the magnetic head itself and its configuration is not mentioned therein.
The invention is designed to overcome the foregoing problems. It is an object to provide a magnetic head with a surface (ABS), which is to face a recording medium, being appropriately roughed without damaging the head core part, a method of manufacturing the same, and a magnetic disk apparatus.
A magnetic head of the invention comprises a base body and a head core part formed on the base body including at least either a magnetic head element for writing or a magnetic head element for reading. In the magnetic head, an end face of the base body and an end face of the head core part form a flat surface which is to face a recording medium while the end face of the base body is rougher than the end face of the head core part.
A method of manufacturing a magnetic head of the invention which comprises a base body and a head core part formed on the base body including at least either a magnetic head element for writing or a magnetic head element for reading includes steps of: forming a flat surface including an end face of the base body and an end face of the head core part, the flat surface being to face a recording medium, after forming the head core part on the base body; and selectively roughing the end face of the base body of the flat surface by performing a chemical processing thereon.
A magnetic disk apparatus of the invention comprises a magnetic head which includes a base body and a head core part formed on the base body including at least either a magnetic head element for writing or a magnetic head element for reading. In the magnetic disk apparatus, an end face of the base body and an end face of the head core part form a flat surface which is to face a recording medium while the end face of the base body is rougher than the end face of the head core part.
In each of the magnetic head, the method of manufacturing the same and the magnetic disk apparatus of the invention, an end face of the base body among a flat surface which includes the end face of the base body and an end face of the head core part is selectively roughed so as to make it rougher than the end face of the head core part.
In each of the magnetic head, the method of manufacturing the same and the magnetic disk apparatus of the invention, protrusions of a predetermined height may be formed only on an end face of the base body. The height of the protrusions are preferable to lie within a range of 2 nm to 7 nm.
In each of the magnetic head, the method of manufacturing the same and the magnetic disk apparatus of the invention, it is preferable to construct the base body by dispersing grains made of at least either metal or metallic compound into a base material made of insulating substance. Specifically, it is preferable to be constructed by dispersing at least titanium carbide (TiC) into a base material made of aluminum oxide (Al2O3).
In each of the magnetic head, the method of manufacturing the same and the magnetic disk apparatus of the invention, the protrusions may be formed on an end face of the base body by performing a predetermined chemical processing to the grains exposed on the end face of the base body. The chemical processing may be performed in a plasma atmosphere of a predetermined chemical element. It is preferable to be performed by an oxidation processing.
In the method of manufacturing the magnetic head of the invention, after the step of forming the flat surface, a step of performing a surface processing on the end face of the base body may be included before the step of roughing the surface. As an example of the surface processing, there is a processing including a step of forming a predetermined coating on the end face of the base body and a step of removing the coating. As coating, a photoresist film used in photolithography may be formed.
Other and further object, features and advantages of the invention will appear more fully from the following description.